Source file src/pkg/net/sock.go

     1	// Copyright 2009 The Go Authors.  All rights reserved.
     2	// Use of this source code is governed by a BSD-style
     3	// license that can be found in the LICENSE file.
     4	
     5	// Sockets
     6	
     7	package net
     8	
     9	import (
    10		"io"
    11		"os"
    12		"reflect"
    13		"syscall"
    14	)
    15	
    16	// Boolean to int.
    17	func boolint(b bool) int {
    18		if b {
    19			return 1
    20		}
    21		return 0
    22	}
    23	
    24	// Generic socket creation.
    25	func socket(net string, f, p, t int, la, ra syscall.Sockaddr, toAddr func(syscall.Sockaddr) Addr) (fd *netFD, err os.Error) {
    26		// See ../syscall/exec.go for description of ForkLock.
    27		syscall.ForkLock.RLock()
    28		s, e := syscall.Socket(f, p, t)
    29		if e != 0 {
    30			syscall.ForkLock.RUnlock()
    31			return nil, os.Errno(e)
    32		}
    33		syscall.CloseOnExec(s)
    34		syscall.ForkLock.RUnlock()
    35	
    36		setKernelSpecificSockopt(s, f)
    37	
    38		if la != nil {
    39			e = syscall.Bind(s, la)
    40			if e != 0 {
    41				closesocket(s)
    42				return nil, os.Errno(e)
    43			}
    44		}
    45	
    46		if fd, err = newFD(s, f, p, net); err != nil {
    47			closesocket(s)
    48			return nil, err
    49		}
    50	
    51		if ra != nil {
    52			if err = fd.connect(ra); err != nil {
    53				fd.Close()
    54				return nil, err
    55			}
    56		}
    57	
    58		sa, _ := syscall.Getsockname(s)
    59		laddr := toAddr(sa)
    60		sa, _ = syscall.Getpeername(s)
    61		raddr := toAddr(sa)
    62	
    63		fd.setAddr(laddr, raddr)
    64		return fd, nil
    65	}
    66	
    67	func setsockoptInt(fd *netFD, level, opt int, value int) os.Error {
    68		return os.NewSyscallError("setsockopt", syscall.SetsockoptInt(fd.sysfd, level, opt, value))
    69	}
    70	
    71	func setsockoptNsec(fd *netFD, level, opt int, nsec int64) os.Error {
    72		var tv = syscall.NsecToTimeval(nsec)
    73		return os.NewSyscallError("setsockopt", syscall.SetsockoptTimeval(fd.sysfd, level, opt, &tv))
    74	}
    75	
    76	func setReadBuffer(fd *netFD, bytes int) os.Error {
    77		fd.incref()
    78		defer fd.decref()
    79		return setsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_RCVBUF, bytes)
    80	}
    81	
    82	func setWriteBuffer(fd *netFD, bytes int) os.Error {
    83		fd.incref()
    84		defer fd.decref()
    85		return setsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_SNDBUF, bytes)
    86	}
    87	
    88	func setReadTimeout(fd *netFD, nsec int64) os.Error {
    89		fd.rdeadline_delta = nsec
    90		return nil
    91	}
    92	
    93	func setWriteTimeout(fd *netFD, nsec int64) os.Error {
    94		fd.wdeadline_delta = nsec
    95		return nil
    96	}
    97	
    98	func setTimeout(fd *netFD, nsec int64) os.Error {
    99		if e := setReadTimeout(fd, nsec); e != nil {
   100			return e
   101		}
   102		return setWriteTimeout(fd, nsec)
   103	}
   104	
   105	func setReuseAddr(fd *netFD, reuse bool) os.Error {
   106		fd.incref()
   107		defer fd.decref()
   108		return setsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, boolint(reuse))
   109	}
   110	
   111	func bindToDevice(fd *netFD, dev string) os.Error {
   112		// TODO(rsc): call setsockopt with null-terminated string pointer
   113		return os.EINVAL
   114	}
   115	
   116	func setDontRoute(fd *netFD, dontroute bool) os.Error {
   117		fd.incref()
   118		defer fd.decref()
   119		return setsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_DONTROUTE, boolint(dontroute))
   120	}
   121	
   122	func setKeepAlive(fd *netFD, keepalive bool) os.Error {
   123		fd.incref()
   124		defer fd.decref()
   125		return setsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_KEEPALIVE, boolint(keepalive))
   126	}
   127	
   128	func setNoDelay(fd *netFD, noDelay bool) os.Error {
   129		fd.incref()
   130		defer fd.decref()
   131		return setsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_NODELAY, boolint(noDelay))
   132	}
   133	
   134	func setLinger(fd *netFD, sec int) os.Error {
   135		var l syscall.Linger
   136		if sec >= 0 {
   137			l.Onoff = 1
   138			l.Linger = int32(sec)
   139		} else {
   140			l.Onoff = 0
   141			l.Linger = 0
   142		}
   143		fd.incref()
   144		defer fd.decref()
   145		e := syscall.SetsockoptLinger(fd.sysfd, syscall.SOL_SOCKET, syscall.SO_LINGER, &l)
   146		return os.NewSyscallError("setsockopt", e)
   147	}
   148	
   149	type UnknownSocketError struct {
   150		sa syscall.Sockaddr
   151	}
   152	
   153	func (e *UnknownSocketError) String() string {
   154		return "unknown socket address type " + reflect.TypeOf(e.sa).String()
   155	}
   156	
   157	type writerOnly struct {
   158		io.Writer
   159	}
   160	
   161	// Fallback implementation of io.ReaderFrom's ReadFrom, when sendfile isn't
   162	// applicable.
   163	func genericReadFrom(w io.Writer, r io.Reader) (n int64, err os.Error) {
   164		// Use wrapper to hide existing r.ReadFrom from io.Copy.
   165		return io.Copy(writerOnly{w}, r)
   166	}
The Go Programming Language

Source file src/pkg/net/sock.go
